Biblio

In a research community, the provenance sharing of scientific workflows can enhance distributed research cooperation, experiment reproducibility verification and experiment repeatedly doing. Considering that scientists in such a community are often in a loose relation and distributed geographically, traditional centralized provenance sharing architectures have shown their disadvantages in poor trustworthiness, reliabilities and efficiency. Additionally, they are also difficult to protect the rights and interests of data providers. All these have been largely hindering the willings of distributed scientists to share their workflow provenance. Considering the big advantages of blockchain in decentralization, trustworthiness and high reliability, an approach to sharing scientific workflow provenance based on blockchain in a research community is proposed. To make the approach more practical, provenance is handled on-chain and original data is delivered off-chain. A kind of block structure to support efficient provenance storing and retrieving is designed, and an algorithm for scientists to search workflow segments from provenance as well as an algorithm for experiments backtracking are provided to enhance the experiment result sharing, save computing resource and time cost by avoiding repeated experiments as far as possible. Analyses show that the approach is efficient and effective.

Known for powering cryptocurrencies such as Bitcoin and Ethereum, blockchain is seen as a disruptive technology capable of revolutionizing a wide variety of domains, ranging from finance to governance, by offering superior security, reliability, and transparency founded upon a decentralized and democratic computational model. In this tutorial, we first present the original Bitcoin design, along with Ethereum and Hyperledger, and reflect on their design choices through the academic lens. We further provide an overview of potential applications and associated research challenges, as well as a survey of ongoing research directions related to byzantine fault-tolerance consensus protocols. We highlight the new opportunities blockchain creates for building the next generation of secure middleware platforms and explore the possible interplay between AI and blockchains, or more specifically, how blockchain technology can enable the notion of "decentralized intelligence." We conclude with a walkthrough demonstrating the process of developing a decentralized application using a popular Smart Contract language (Solidity) over the Ethereum platform

The mining and metals industry is a critical component of the global economy. However, many operational and commercial practices remain inefficient and antiquated, leading to critical data omissions, security vulnerabilities, and even corruption. Mining supply chain faces several challenges like traceability, transparency, interoperability between supplier platforms and so on. Traditional systems are inefficient and hence this paper explores the use of an emerging digital technology named blockchain. The blockchain is a distributed digital ledger that keeps a record of every transaction securely and reliably without the need of third parties that reduces the exposure of the data to hackers. Blockchain technology improves productivity by replacing the standard contract with smart contracts. This paper outlines several key applications of blockchain for the mining industry.

Traditionally, a Certification Authority (CA) is required to sign, manage, verify and revoke public key certificates. Multiple CAs together form the CA-based Public Key Infrastructure (PKI). The use of a PKI forces one to place trust in the CAs, which have proven to be a single point-of-failure on multiple occasions. Blockchain has emerged as a transformational technology that replaces centralized trusted third parties with a decentralized, publicly verifiable, peer-to-peer data store which maintains data integrity among nodes through various consensus protocols. In this paper, we deploy three blockchain-based alternatives to the CA-based PKI for supporting IoT devices, based on Emercoin Name Value Service (NVS), smart contracts by Ethereum blockchain, and Ethereum Light Sync client. We compare these approaches with CA-based PKI and show that they are much more efficient in terms of computational and storage requirements in addition to providing a more robust and scalable PKI.

Current anti-counterfeiting supply chains rely on a centralized authority to combat counterfeit products. This architecture results in issues such as single point processing, storage, and failure. Blockchain technology has emerged to provide a promising solution for such issues. In this paper, we propose the block-supply chain, a new decentralized supply chain that detects counterfeiting attacks using blockchain and Near Field Communication (NFC) technologies. Block-supply chain replaces the centralized supply chain design and utilizes a new proposed consensus protocol that is, unlike existing protocols, fully decentralized and balances between efficiency and security. Our simulations show that the proposed protocol offers remarkable performance with a satisfactory level of security compared to the state of the art consensus protocol Tendermint.

Quality of conversational agents is important as users have high expectations. Consequently, poor interactions may lead to the user abandoning the system. In this paper, we propose a framework to test the quality of conversational agents. Our solution transforms working input that the conversational agent accurately recognises to generate divergent input examples that introduce complexity and stress the agent. As the divergent inputs are based on known utterances for which we have the 'normal' outputs, we can assess how robust the conversational agent is to variations in the input. To demonstrate our framework we built ChitChatBot, a simple conversational agent capable of making casual conversation.

In recent years, biometric techniques (e.g., fingerprint or iris) are increasingly integrated into mobile devices to offer security advantages over traditional practices (e.g., passwords and PINs) due to their ease of use in user authentication. However, existing biometric systems are with controversy: once divulged, they are compromised forever - no one can grow a new fingerprint or iris. This work explores a truly cancelable brain-based biometric system for mobile platforms (e.g., smart headwear). Specifically, we present a new psychophysiological protocol via non-volitional brain response for trustworthy mobile authentication, with an application example of smart headwear. Particularly, we address the following research challenges in mobile biometrics with a theoretical and empirical combined manner: (1) how to generate reliable brain responses with sophisticated visual stimuli; (2) how to acquire the distinct brain response and analyze unique features in the mobile platform; (3) how to reset and change brain biometrics when the current biometric credential is divulged. To evaluate the proposed solution, we conducted a pilot study and achieved an f -score accuracy of 95.46% and equal error rate (EER) of 2.503%, thereby demonstrating the potential feasibility of neurofeedback based biometrics for smart headwear. Furthermore, we perform the cancelability study and the longitudinal study, respectively, to show the effectiveness and usability of our new proposed mobile biometric system. To the best of our knowledge, it is the first in-depth research study on truly cancelable brain biometrics for secure mobile authentication.

Detecting violence in videos through automatic means is significant for law enforcement and analysis of surveillance cameras with the intent of maintaining public safety. Moreover, it may be a great tool for protecting children from accessing inappropriate content and help parents make a better informed decision about what their kids should watch. However, this is a challenging problem since the very definition of violence is broad and highly subjective. Hence, detecting such nuances from videos with no human supervision is not only technical, but also a conceptual problem. With this in mind, we explore how to better describe the idea of violence for a convolutional neural network by breaking it into more objective and concrete parts. Initially, our method uses independent networks to learn features for more specific concepts related to violence, such as fights, explosions, blood, etc. Then we use these features to classify each concept and later fuse them in a meta-classification to describe violence. We also explore how to represent time-based events in still-images as network inputs; since many violent acts are described in terms of movement. We show that using more specific concepts is an intuitive and effective solution, besides being complementary to form a more robust definition of violence. When compared to other methods for violence detection, this approach holds better classification quality while using only automatic features.

We study secret sharing schemes for general (non-threshold) access structures. A general secret sharing scheme for n parties is associated to a monotone function F:\0,1\n$\rightarrow$\0,1\. In such a scheme, a dealer distributes shares of a secret s among n parties. Any subset of parties T $\subseteq$ [n] should be able to put together their shares and reconstruct the secret s if F(T)=1, and should have no information about s if F(T)=0. One of the major long-standing questions in information-theoretic cryptography is to minimize the (total) size of the shares in a secret-sharing scheme for arbitrary monotone functions F. There is a large gap between lower and upper bounds for secret sharing. The best known scheme for general F has shares of size 2n-o(n), but the best lower bound is $Ømega$(n2/logn). Indeed, the exponential share size is a direct result of the fact that in all known secret-sharing schemes, the share size grows with the size of a circuit (or formula, or monotone span program) for F. Indeed, several researchers have suggested the existence of a representation size barrier which implies that the right answer is closer to the upper bound, namely, 2n-o(n). In this work, we overcome this barrier by constructing a secret sharing scheme for any access structure with shares of size 20.994n and a linear secret sharing scheme for any access structure with shares of size 20.999n. As a contribution of independent interest, we also construct a secret sharing scheme with shares of size 2Õ($\surd$n) for 2n n/2 monotone access structures, out of a total of 2n n/2$\cdot$ (1+O(logn/n)) of them. Our construction builds on recent works that construct better protocols for the conditional disclosure of secrets (CDS) problem.

Security is a vital aspect of industrial control systems since they are used in critical infrastructures and manufacturing processes. As demonstrated by the increasing number of emerging exploits, securing such systems is still a challenge as the employed fieldbus technologies do not offer intrinsic support for basic security objectives. In this work we discuss some security aspects of DeviceNet, a communication protocol widely used for control applications especially in the North American industrial sector. Having the Controller Area Network (CAN) protocol at its base, DeviceNet inherits all the vulnerabilities that were already illustrated on CAN in-vehicle communication. We discuss how the lack of security in DeviceNet can be exploited and point on the fact that these vulnerabilities can be modelled by existing formal verification tools and countermeasures can be put in place.

An information system is only as secure as its weakest point. In many information systems that remains to be the human factor, despite continuous attempts to educate the users about the importance of password security and enforcing password creation policies on them. Furthermore, not only do the average users' password creation and management habits remain more or less the same, but the password cracking tools, and more importantly, the computer hardware, keep improving as well. In this study, we performed a broad targeted attack combining several well-established cracking techniques, such as brute-force, dictionary, and hybrid attacks, on the passwords used by the students of a Slovenian university to access the online grading system. Our goal was to demonstrate how easy it is to crack most of the user-created passwords using simple and predictable patterns. To identify differences between them, we performed an analysis of the cracked and uncracked passwords and measured their strength. The results have shown that even a single low to mid-range modern GPU can crack over 95% of passwords in just few days, while a more dedicated system can crack all but the strongest 0.5% of them.

In 2009, Craig Gentry introduced the first "fully" homomorphic encryption scheme allowing arbitrary circuits to be evaluated on encrypted data. Homomorphic encryption is a very powerful cryptographic primitive, though it has often been viewed by practitioners as too inefficient for practical applications. However, the performance of these encryption schemes has come a long way from that of Gentry's original work: there are now several well-maintained libraries implementing homomorphic encryption schemes and protocols demonstrating impressive performance results, alongside an ongoing standardization effort by the community. In this tutorial we survey the existing homomorphic encryption landscape, providing both a general overview of the state of the art, as well as a deeper dive into several of the existing libraries. We aim to provide a thorough introduction to homomorphic encryption accessible by the broader computer security community. Several of the presenters are core developers of well-known publicly available homomorphic encryption libraries, and organizers of the homomorphic encryption standardization effort \textbackslashtextbackslashhrefhttp://homomorphicencryption.org/. This tutorial is targeted at application developers, security researchers, privacy engineers, graduate students, and anyone else interested in learning the basics of modern homomorphic encryption.The tutorial is divided into two parts: Part I is accessible by everyone comfortable with basic college-level math; Part II will cover more advanced topics, including descriptions of some of the different homomorphic encryption schemes and libraries, concrete example applications and code samples, and a deeper discussion on implementation challenges. Part II requires the audience to be familiar with modern C++.

Marginal tables are the workhorse of capturing the correlations among a set of attributes. We consider the problem of constructing marginal tables given a set of user's multi-dimensional data while satisfying Local Differential Privacy (LDP), a privacy notion that protects individual user's privacy without relying on a trusted third party. Existing works on this problem perform poorly in the high-dimensional setting; even worse, some incur very expensive computational overhead. In this paper, we propose CALM, Consistent Adaptive Local Marginal, that takes advantage of the careful challenge analysis and performs consistently better than existing methods. More importantly, CALM can scale well with large data dimensions and marginal sizes. We conduct extensive experiments on several real world datasets. Experimental results demonstrate the effectiveness and efficiency of CALM over existing methods.

In this paper, a framework for Moving Target Defense is introduced. This framework bases on three pillars: network address mutation, communication stack randomization and the dynamic deployment of decoys. The network address mutation is based on the concept of domain generation algorithms, where different features are included to fulfill the system requirements. Those requirements are time dependency, unpredictability and determinism. Communication stack randomization is applied additionally to increase the complexity of reconnaissance activity. By employing communication stack randomization, previously fingerprinted systems do not only differ in the network address but also in their communication pattern behavior. And finally, decoys are integrated into the proposed framework to detect attackers that have breached the perimeter. Furthermore, attacker's resources can be bound by interacting with the decoy systems. Additionally, the framework can be extended with more advanced Moving Target Defense methods such as obscuring port numbers of services.

The technological development of automated vehicles opens novel cybersecurity threats and risks for road safety. Increased connectivity often results in increased risks of a cyber-security attacks, which is one of the biggest challenges for the automotive industry that undergoes a profound transformation. State of the art studies evaluated potential attacks and recommended possible measures, from technical and organizational perspective to face these challenges. In this position paper, we review these techniques and methods and show that some of the different solutions complement each other while others overlap or are even incompatible or contradictory. Based on this gap analysis, we advocate for the need of a comprehensive framework that integrates technical and organizational mitigation measures to enhance the cybersecurity of automotive vehicles.

Real-Time Ethernet has become the major communication technology for modern automation and industrial control systems. On the one hand, this trend increases the need for an automation-friendly security solution, as such networks can no longer be considered sufficiently isolated. On the other hand, it shows that, despite diverging requirements, the domain of Operational Technology (OT) can derive advantage from high-volume technology of the Information Technology (IT) domain. Based on these two sides of the same coin, we study the challenges and prospects of approaches to communication security in real-time Ethernet automation systems. In order to capitalize the expertise aggregated in decades of research and development, we put a special focus on the reuse of well-established security technology from the IT domain. We argue that enhancing such technology to become automation-friendly is likely to result in more robust and secure designs than greenfield designs. Because of its widespread deployment and the (to this date) nonexistence of a consistent security architecture, we use PROFINET as a showcase of our considerations. Security requirements for this technology are defined and different well-known solutions are examined according their suitability for PROFINET. Based on these findings, we elaborate the necessary adaptions for the deployment on PROFINET.

Blömer et al. have presented a cloud architecture for enabling fine-grained cryptographic access control to data in the cloud. The architecture is intended to provide this service to large-scale orgnaizations. We revisit the cloud architecture, and enrich it with searchable encryption. In the process, we identify some shortcomings of Blömer et al.'s architecture, that prevent many cryptographic primitives from being implemented within the framework of the architecture. Subsequently, we propose fixes to these issues. As a result, we are able to propose a concrete instantiation of searchable encryption, in the form of Bost's $Σ$o$\phi$o$ς$ scheme, in Blömer et al.'s architecture. Moreover, with our fixes, other primitives can be adapted to the architecture as well.

Cloud computing is an emerging technology that can provide organizations, enterprises and governments with cheaper, more convenient and larger scale computing resources. However, cloud computing will bring potential risks and threats, especially on security and privacy. We make a survey on potential threats and risks and existing solutions on cloud security and privacy. We also put forward some problems to be addressed to provide a secure cloud computing environment.

We report time-domain measurements of acoustic-wave-induced magnetization dynamics in magnetic tunnel junctions. The acoustic pulses are generated by femtosecond laser excitation and interact with the magnetization through magnetoelastic coupling. The induced magnetization precession is not only dependent on the externally applied magnetic field, but also on the laser excitation position. The presented method even allows us to coherently control the precession using two laser pulses at various magnetic fields and excitation positions.

In order to cater the growing spectrum demands of large scale future 5G Internet of Things (IoT) applications, Dynamic Spectrum Access (DSA) based networks are being proposed as a high-throughput and cost-effective solution. However the lack of understanding of DSA paradigm's inherent security vulnerabilities on IoT networks might become a roadblock towards realizing such spectrum aware 5G vision. In this paper, we make an attempt to understand how such inherent DSA vulnerabilities in particular Spectrum Sensing Data Falsification (SSDF) attacks can be exploited by collaborative group of selfish adversaries and how that can impact the performance of spectrum aware IoT applications. We design a utility based selfish adversarial model mimicking collaborative SSDF attack in a cooperative spectrum sensing scenario where IoT networks use dedicated environmental sensing capability (ESC) for spectrum availability estimation. We model the interactions between the IoT system and collaborative selfish adversaries using a leader-follower game and investigate the existence of equilibrium. Using simulation results, we show the nature of adversarial and system utility components against system variables. We also explore Pareto-optimal adversarial strategy design that maximizes the attacker utility for varied system strategy spaces.

This paper deals with an on-line non-destructive inspection system by using hammering sounds based on the combination of support vector machine and a heuristic algorithm. In machine learning algorithms, the perfect performance is hard to attain and it is newly suggested that a heuristic algorithm redeeming this insufficiency is connected to the support vector machine as a post-process. The experimental results show that the combination of support vector machine and the heuristic algorithm attains 100% detection of defective pieces with 18.4% of erroneous determination of non-defective pieces within the upper limit of given processing time.

Due to recent data explosion, scientists invest most of their efforts in the collection of data needed for research. In this paper, we address the community-driven data curation system which is essential to enhancing data understandability and reusability, thereby reducing the efforts for data collection. The curation system focuses on the interlinking between data and their related literatures to capture and organize the associations among research output. The system also focuses on domain-specific contextual information to help users understand data. A global research group in protein study has adopted the system to build a community-driven curated database and established a guideline for scientific discovery.

Networks established among nanomachines, also called nanonetworks, are crucial since, a single nanomachine most likely cannot handle task by itself. At the nano scale, electromagnetic waves lose their effectiveness. Molecular communication via diffusion (MCvD) is a new concept that aims to solve this problem. Information is carried out by either the type of molecules, or their concentration. The robustness of this communication method, as in the example of classical communication, is very important. Channel coding is the component that make communication less erroneous. If the desired error performance is high, channel coding is mandatory. In this paper, the performance of Bose-Chaudhuri-Hocquenghem (BCH) and Reed-Solomon (RS) codes for MCvD are evaluated by simulation and results are analyzed.

Outliers are unusual data points which are inconsistent with other observations. Human error, mechanical faults, fraudulent behavior, instrument error, and changes in the environment are some reasons to arise outliers. Several types of outlier detection algorithms are developed and a number of surveys and overviews are performed to distinguish their advantages and disadvantages. Multivariate outlier detection algorithms are widely used among other types, therefore we concentrate on this type. In this work a comparison between effects of multivariate outlier detection algorithms on machine learning problems is performed. For this purpose, three multivariate outlier detection algorithms namely distance based, statistical based and clustering based are evaluated. Benchmark datasets of Heart disease, Breast cancer and Liver disorder are used for the experiments. To identify the effectiveness of mentioned algorithms, the above datasets are classified by Support Vector Machines (SVM) before and after outlier detection. Finally a comparative review is performed to distinguish the advantages and disadvantages of each algorithm and their respective effects on accuracy of SVM classifiers.

To be applicable to high user request workloads, web caching strategies benefit from low implementation and update effort. In this regard, the Least Recently Used (LRU) replacement principle is a simple and widely-used method. Despite its popularity, LRU has deficits in the achieved hit rate performance and cannot consider transport and network optimization criteria for selecting content to be cached. As a result, many alternatives have been proposed in the literature, which improve the cache performance at the cost of higher complexity. In this work, we evaluate the implementation complexity and runtime performance of LRU, Least Frequently Used (LFU), and score based strategies in the class of fast O(1) updates with constant effort per request. We implement Window LFU (W-LFU) within this class and show that O(1) update effort can be achieved. We further compare fast update schemes of Score Gated LRU and new Score Gated Polling (SGP). SGP is simpler than LRU and provides full flexibility for arbitrary score assessment per data object as information basis for performance optimization regarding network cost and quality measures.